Which local anesthetic can be used without a vasoconstrictor due to its low vasodilating properties?

Mepivacaine is unique among local anesthetics because it has relatively low vasodilating properties compared to the others listed. This characteristic allows it to be effective even without the addition of a vasoconstrictor.

Typically, local anesthetics cause vasodilation, which can lead to increased blood flow in the area where the anesthetic was administered. This increased blood flow may result in a shorter duration of action because the anesthetic is carried away from the site more quickly. Mepivacaine's lower vasodilatory effect means that it can provide adequate anesthetic effects for procedures without the need for a vasoconstrictor to prolong its duration or to reduce systemic absorption.

In contrast, the other local anesthetics mentioned, such as lidocaine and bupivacaine, typically exhibit stronger vasodilating properties, making the use of a vasoconstrictor more common for procedures requiring prolonged anesthesia. Articaine, while effective, is also typically used with a vasoconstrictor in many situations due to its higher vasodilating tendencies. Therefore, mepivacaine stands out for its ability to work effectively on its own without compromising the effectiveness of the anesthesia.